相关论文: STIS UV spectroscopy of early B supergiants in M31

We present terminal velocities of M33 B-supergiants, obtained from STIS HST spectra as part of our programme to investigate the Wind Momentum -- Luminosity Relationship (WLR) in the Local Group. Terminal velocities are derived from their…

The Balmer lines of four A Ia - supergiants (spectral type A0 to A3) and fourteen B Ia and Ib - supergiants (spectral type B0 to B3) in the solar neighbourhood are analyzed by means of NLTE unified model atmospheres to determine the…

Despite a resurgence of effort over the last decade in the area of massive stars there is still ambiguity over their evolutionary path, contamination of their surface abundances and the behaviour of their stellar winds. Here 10 SMC B-type…

We present the first quantitative UV spectroscopic analysis of resolved OB stars in IC1613. Because of its alleged very low metallicity (<~1/10 Zo, from HII regions), studies in this Local Group dwarf galaxy could become a significant step…

We present high quality spectroscopic data for two massive stars in the OB10 association of M31, OB10-64 (B0Ia) and OB10-WR1 (WC6). Medium resolution spectra of both stars were obtained using the ISIS spectrograph on the William Hershel…

We present ultraviolet spectra from the Space Telescope Imaging Spectrograph (STIS) of 12 early B-type stars in the Small Magellanic Cloud (SMC), comprising 9 supergiants and 3 giants. A morphological comparison with Galactic analogues is…

We have carried out the wind analysis of six A-type supergiants in NGC 300. The derived Wind Momentum-Luminosity Relationship is compared with that of Galactic and M31 blue supergiants and with theoretical models.

Ultraviolet spectra from the Space Telescope Imaging Spectrograph (STIS) are used to determine terminal velocities for 11 O and B-type giants and supergiants in the Small Magellanic Cloud (SMC) from the Si IV and C IV resonance lines. Using…

Spectroscopic analyses of 7 SMC B-type supergiants and 1 giant have been undertaken using high resolution optical data obtained on the VLT with UVES. FASTWIND, a non-LTE, spherical,line-blanketed model atmosphere code was used to derive…

We present the largest sample to-date of intermediate-resolution blue-to-red optical spectra of B-type supergiants in M31 and undertake the first survey of diffuse interstellar bands (DIBs) in this galaxy. Spectral classifications, radial…

Multi-object spectroscopic observations of blue supergiants in NGC 3621, a spiral galaxy at a distance of 6.7 Mpc, carried out with the ESO VLT and FORS are presented. We demonstrate the feasibility of quantitative stellar spectroscopy at…

We apply the NLTE atmosphere code FASTWIND to perform a spectroscopic study of a small sample of Galactic B-supergiants from B0 to B9. By means of the resulting data and incorporating additional datasets from alternative studies, we…

The spectra of two early B-type supergiant stars in the Sculptor spiral galaxy NGC 300 are analysed by means of non-LTE line blanketed unified model atmospheres, aimed at determining their chemical composition and the fundamental stellar…

The mass outflows in T Tauri stars (TTS) are thought to be an effective mechanism to remove angular momentum during the pre-main-sequence contraction of a low-mass star. The most powerful winds are observed at the FUor stage of stellar…

We present optical studies of the physical and wind properties, plus CNO chemical abundances, of 25 O9.5-B3 Galactic supergiants. We employ non-LTE, line blanketed, extended model atmospheres, which provide a modest downward revision in the…

Variable B supergiants (BSGs) constitute a heterogeneous group of stars with complex photometric and spectroscopic behaviours. They exhibit mass-loss variations and experience different types of oscillation modes, and there is growing…

We have conducted a survey of FUSE spectra of 235 Galactic B-type stars in order to determine the boundaries in the H-R diagram for the production of the superion O VI in their winds. By comparing the locations and morphology of otherwise…

We present HST/STIS Ultraviolet spectra of the six known Ofpe/WN9 stars (``slash stars'') in M33. These stars were selected for showing the characteristics of the Ofpe/WN9 class from previous optical ground-based spectroscopy. The UV…

Accurate determination of mass-loss rates from massive stars is important to understanding stellar and galactic evolution and enrichment of the interstellar medium. Large-scale structure and variability in stellar winds have significant…

We present the first results of a spectroscopic study of young massive stars in the SMC High Excitation Blob N81. These stars have Mv values which are ~ 2 mag smaller than those of nor mal dwarf stars. Their UV STIS spectra reveal features…